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 We all know about the health benefits of exercise. As the phrase goes, it can add years to your life and life to your years. But just how much exercise do you need to reap any fitness benefit?
“The amount of physical activity you need obviously depends on your goals, be it to manage stress, lower your blood pressure, lose weight, or participate in sports,” says Dr Ben Tan, chairman of the Exercise is Medicine, Singapore Task Force.
For general health purposes, the WHO recommends these exercise guidelines for adults aged 18-64:
1. At least 150 minutes of moderate-intensity aerobic physical activity throughout the week.
2. If the intensity of the aerobic physical activity is vigorous, duration can be halved (75 minutes).
3. Total exercise time can be split in 10 minute increments.
4. Muscle-strengthening activities should be performed at least 2 days a week. Following these guidelines will improve cardio-respiratory and muscular fitness, bone health, as well as reduce the risk of diseases and depression, according to the WHO.
What is moderate intensity?
The target intensity of exercise is a function of each individual’s fitness level. “To achieve moderate intensity, you should exercise at a perceived exertion rate of 3 or 4, on a scale from 1 to 10”, says Ms Elsa Leung, physiotherapist at Changi General Hospital. On this scale, 1 would be defined as “No effort at all” and 10 “Almost maximum effort”.
A rule of thumb: If you can talk but can’t sing while doing your exercise, you’re in the moderate zone.
Can the muscle-strengthening activities be combined with the aerobic activity?
“If you’re short on time, you can even combine your cardiovascular and strength training into a single session, through circuit training. This is where you move from one resistance training station to the next with a minimal rest interval,” suggests Dr Tan, who heads the Changi Sports Medicine Centre and Singapore Sports Medicine Centre.
What if your specific fitness goal is to lose weight?
If you want to lose weight with exercise alone, you need to aim for about 250 minutes of moderate-intensity exercise per week, says Dr Tham Kwang Wei, director of the Weight Management Program at the LIFE Centre of Singapore General Hospital.
Aerobic exercise is the best form of exercise for weight loss, adds Dr Tham. Examples of aerobic exercise are brisk walking, cycling, roller-blading and swimming.
How long does it take for the body to deplete its built-in reserves of energy and start burning fat?
“We have about 2,000 kcal worth of energy stored in the form of carbohydrates. It takes more than 120 minutes to deplete this (i.e. to “hit the wall”) and become almost solely dependent on fat burning to deliver the energy,” says Dr Ben Tan.
How to break the monotony of exercise?
For fitter individuals who have grown bored with exercising at a steady, monotonous pace, Dr Tan suggests high-impact interval training, also known as HIIT, as an alternative. “It pushes the heart rate higher, leading to increased fitness, while burning more calories in a shorter time frame.”
A word of caution: Those with cardiovascular risk factors should clear with their doctors before trying this or any other form of exercise. |